docs: def objects_patch(self, bucket, key, info):
      """Updates the metadata associated with an object.
  
      Args:
        bucket: the name of the bucket containing the object.
        key: the key of the object being updated.
        info: the metadata to update.
      Returns:
        A parsed object information dictionary.
      Raises:
        Exception if there is an error performing the operation.
      """
      url = Api._ENDPOINT + (Api._OBJECT_PATH % (bucket, Api._escape_key(key)))
      return google.datalab.utils.Http.request(url, method='PATCH', data=info,
                                               credentials=self._credentials)